Year	%
2000	23.5
2001	22.9
2002	22.5
2003	22.3
2004	22.3
2005	22.3
2006	22.2
2007	22.3
2008	23
2009	23.8
2010	24.4
2011	24.8
2012	25.4
2013	25.2
2014	24.4
2015	24.2
2016	23.9
2017	23.8
2018	23.9
2019	23.9